Engine cylinder



Aug. 2s, 192s. y 1,682,436

Y c. G. sPRAn ENGINE CYLINDER Filed July 19, 1926 2 Sheets-Sheet l c. G. sPRADO ENGINE CYLINDER Aug. 2s, 1921s.

' 2 Slieets-Sheet 2 Filed July 19, 1926 Naai/Y 5 IIA Patented Aug. 28, 1928.

: UNITED SrATEsv CARL G. SPRADO, OF MILWAUKEE, WISCONSIN, ASSIGNOR To AnnIsOHALMEnsMAN- UFAOTURING COMPANY, OF MILWAUKEE, WIsoOINsIN, A CORPORATION or DELA;

wann Application filed July 19,

facturing cylinders in order to adapt theV Same to withstand extreme variations in temperature, without destruction. A further object of `the invention is to provide simple and efficient means for strengthening the structure of cast cylinders or the like.

`Considerable diliculty hasheretofore been experienced inthe construction of cylinders for prime movers such as internal combustion engines, in providing a cylinder structure adapted to withstand the service to which such apparatus is ordinarily subjected. A gas engine cylinder'is of necessity a complicated casting, which is required to withstand enormous' stresses due .to the combustion or explosionl of gases therein, and

also due to thefvariationsin temperature to which it issubjected in service. Cast cylinders of this type, are also subjected to enormous stresses resultingr froml uneven cooling and contraction of the* casting l1n the mold,during formation ofthe cylinders. It is an objectof the `present lnvention toprovide an improved cylinder structure especially applicable to large engine or pump cylinders, which Will eiectively accommodate or resist any normal stresses to which It may be subjected eitherV during construction thereof or during subsequent operation of the machine.

A clear conception ofn an'embodiment of the invention `and of the mode of constructing cylinders in accordance therewith, `may be had by `referring to the drawings accompanying and `forming a partofthis specication in which like reference characters designate the same Or.` similar parts in the various` Fig. 2 is a part sectional top view ofthe improved gas enginecylinder.

Fig. 3' is a transverse vertical section4 ENGINE CYLINDER.

19.26. Serial No. 123,585..

through the improved gas engine cylinder, the portion to the right of the center line of the figure being a section through the medial portion of the cylinder, and the other half Lof the figure illustrating a section through an end portion of the cylinder. Fig. 4 is a part sectional top view through another form of gasenginecylinder embodying the invention. n j Fig. 5 is a. transverse vertical section through the medial and end cylinder disclosed in Fig. 4. Fig. 6 is a 'transverse vertical section through the medial and end portions of another form of cylinder embodying the in-` vention. e

Fig. 7 is a ragmentarytransversc vertical section through the medialand end portions of still another form of `cylinder embodying the invention. j u

Referring specificallyto Figs.v l to3 in'- clusive, the gas engine cylinder comprises in general an annular inner wall 2 forming a combustion chamber ll, andan outer, wall 3 surrounding and spaced from the inner wall 2 to form an annular jacketspace l2.

The Outer cylinder'y wall?) is provided withv upper and lower end openings,and inlet and discharge valve pockets 4, 10 respectively,

are cast integral with the inner wall 2 and extend outwardly therefrom across the jacket space 12 to points within the; endfopenings of the outer wall.l The valve ypockets 4, l0 while being cast integral withthe inner wall 2 are preferably free from direct cast connection with the outer wall 3. An annularV series of ribs 5 are cast integral with' and connect 'the inner and outerwalls2, 3 intermediate the valve pockets.V The ribs 5 extend longltudinallyl of the cylinder and are formed relatively thin so as to make them Vce laterally deflectable. A5 plurality ofjradially disposed spacing members 6V arealsocast integral with the inner and outer walls 2,V

-vadjacent to the valve pockets 4,110, these members 6 being reelatively thinfandfhence defiectable longitudinally of the cylinder axis. The ribs 5 and `members -6' while spanning the jacket space 12,1 still allow free circulation of cooling` medium through' this jacket. As illustrated inFigs. l to`-3 inclusive of the drawing, the endsof the wallsl 2, 3 `are also free from direct cast'conn'ectlon" and the annularspacesfbetween the wall ends are closed by means of end plates 7. The anoast integral with the inner wall 23 extend nular spaces between the outer ends of the inlet valve pockets 4 and the outer wall 3 are also closed by means of top plates 8, and the spaces between the exhaust valve pockets 10 and the outer wall 3 are likewise closed by means of bottoni plates 9. The closure plates 7, 8, 9 seal the jacket space 12 against possible escape of cooling iiuid which may be admitted and discharged from the jacket in a well known manner.

Referring specifically to Figs. 4 and the gas engine cylinder disclosed therein comprises in general an annular inner wall 13 forming a combustion chamber Q1, and an outer wall 14 surrounding and spaced from the inner wall 13 to provide an annular jacket space 22. The outer wall 14- has upper and lower end openings, and inlet and discharge valve pockets 15, 19, respectively, are cast integral with the inner wall 13 and extend outwardly therefrom across the jacket space 22 to points within the end openings of the outer wall 14. The valve pockets 15, 19 while being cast integral with the inner wallr 13 are preferably free from direct cast connection with the outer wall 14. An annular series of inclined or tangential ribs 1G are cast integral with and connect the inner and outer walls 13, 14, intermediate the valve pockets 15, 19. The ribs 1G extend longitudinally of the cylinder and are formed relatively thin thus making them transversely deectable. A plurality oi" radially disposed spacing members or stay bolts 17 have their ends cast into or integral with the inner and outer cylinder walls adjacent to the valve pockets 15, 19, these bolts being laterally detlectable to permit relative shifting of the walls. The ribs 16 and the bolts 17 while spanning the jacket space 2Q and forming a resilient connection between the inner and the outer wall, permit free circulation of cooling medium through the jacket. The extreme ends of the inner and outer walls 13, 14 may be connected by relatively thin end walls 18 which are cast integral with the cylinder walls but are delectable longitudinally of the cylinder axis. The annular spaces between the outer ends of the inlet valve pockets 15, 19 and the outer wall may be closed by means of plates as shown in Fig. 1, and the walls 18, 14 may be provided with spark plug receiving openings 2O as shown in the drawing.

In the embodiment of the invention specifically illustrated in Fig. 6, an annular inner wall 23 forms the combustion chamber il and is surrounded by a partially polygonal and partly substantially circular outer wall 24 spaced from the inner Vall to forni an annular jacket space 32. The circular end portions 30 of the outer wall 24 are provided with upper and lower end openings, and inlet and discharge valve pockets 25, Q8 which are outwardly therefrom across the jacket space 32 to points within the end openings o't the outer wall Q4. The valve pockets 253. Zit ar.-

iree from direct cast connection with the outer wall portions 30 and the annular openings between the valve pockets and the outer wall may be closed by means of plates as iu Fig. 1.. An annular series of radially disposed ribs QG are cast integral with and connect the inner wall with the medial portions oif the fiat sides of the polygonal inedial portion oi the outer wall 24, these ribs` 2G extending longitudinally ot' the cylinder and being laterally deilectable. A plurality of radially disposed spacing members or stay bolts 27 have their ends cast into the inner wall 23 and into the circular outer wall portion 3() located adjacent to the valve pockets 2S, these stay bolts also being laterally deiieetable. The ribs QG and the members or bolts QT merely connect and provide resilient spacers for the inner and outer walls 23, 24 and do not obstruct the lree circulation of cooling medium through the jacket. The ends oi' the inner and outer walls 23, 24 may be separated as shown in Fig. 1 or they may be joined by end walls as in Fig. 4, and the cylinder walls may be provided with spark plug openings Q9 as shown.

In the embodiment oi the invention speciiically illustrated in Fig. 7, the annular inner wall 33 Aforms a coinlgmstion chamber 41, and is surrounded by a partially serrated and partly substantially circular wall 14 which is spaced from the inner wall 38 to form a jacket space 42. The circular end portions 4() of the outer wall 34 are provided with upper and lower openings, and inlet and discharge valve pockets which are cast integral with the inner wall 33 extend outwardly from this wall across the jacket space 42, to points within the openings oi' the outer wall portions 40. The valve pockets 35 are free from direct cast connection with the outer wall portions 40 and the annular spaces separating the valve pockets from the outer wall may be closed by plates as previously indicated. An annular series of radially disposed ribs 3G connect the inner wall with the innermost portions oi the serrated medial portion of the outer wall 34 and extend longitudinally of the cylinder, the ribs 36 being laterally deflectable. n. plurality of radially disposed spacing ineinbers or stay bolts 37 having their inner ends cast into the inner and outer walls respectively, are located adjacent to the valve pockets 35, these stay bolts likewise being laterally deflectable. The resilient ribs 3b and stay bolts 37 cooperate to connect and to properly space the inner and outer walls 33, 34, and do not obstruct the free circulation of cooling medium through the jacket .Lio

lill

Of the gases tend `to heat the inner walls to` an extremely high degree. In order to reduce to a minimum the temperature of the` inner walls, coolin medium such as water is circulated throng the jacket spaces there by producing considerable difference in temerature between the inner and outer walls. ince the explosions occur periodically, there is alternate heating and cooling of the inner wall, and the rise in temperaturermay also vary in accordance with variations in the characteristics ofthe explosive mixture admitted to the engine. In order to avoid destruction of the cylinder due to such variations in temperature between the outer and the inner walls, it is desirable to provide for relative expansion and contraction of these walls. Due tothe enormous pressures within thecombustion chambers of such cylinders, itis however necessary to utilize the outer wall to externally brace the inner wall.`

Because of the complicated nature of the structure, the casting of such cylinders is also made diiiicult on account of the unequal stresses set up in the various portions of the structure. The outer and inner walls may not cool lat a uniform rate thereby producing enormous stresses in the connections between thesewalls, Any connections provided should therefore be sufficiently resilient to` permit relative expansion andV contraction between the walls during construction of the cylinders, as well as during normal operation.

It will be apparent that with the embodiment of the invention illustrated in Figs. 1, 2 and 3, the outer and inner walls are free to expand 4and contract independently of each other. The laterally deflectalole longitudinal ribs 5 `permitrelative displace# ment of the walls 2, 3 at the medial portion of the cylinder, while the deflectable member 6 permit freerelative expansion of the walls atthe cylinder ends.y The valve pockets 4, 10 which arefree from direct cast connection with, the outer wall 3, likewise permit free relative expansion and contraction of the walls in any direction without danger of crackingthe casting.y A

The embodiments of Figs, 4, 5, 6 and T also permit free relative expansion and contraction of theinner and outer walls in an obvious manner. The deflectable ribs 16, 26, 36 permit free relative displacement ofthe inner and outer walls at the medial portion of the cylinder, while the resilient stay bolts 17, 27, 37 permitrelative displacement of these wallsboth about and along, the axis at thecylinder ends. As inthe caseof Fig. 1, the valve pockets 175,19', 25, 28, 35 are free from direct cast connectionV with the outer walls thereb vpermit-ting --ree-relative dis-1 placement o tlie walls about and along the cylinder axis.' The tangential ribs 16 of Fig. 5 while serving as efficient struts between the two walls merely produce relative displacement of these walls `about the cylinder axis when the ribs 16 expand or con-f tract. lVith the polygonal form of cylinder illustrated in Fig. 6, expansion of the ribs 16 will merely tend to curve the normally Si straight sides of the polygon and -contraction will tend to straighten these sides. With the serrated form of outer wall kdisclosed. in Fig. 7, expansion and contraction of the ribs 86 will be accommodated in anr obvious manner, at the outermost portions of the sei-rations.

It will be thus be notedrthat the invention provides simple and efficient means for effectively accommodating `normal stresses to which. the cylinder structure maybe subjected either during construction thereof or Vduring subsequent Voperation of? the machine. rL lhe connections eifectivelybrace the innerV wall against excessive ressures and do not interfere with the circu ation of cooling medium throughl the jacket space. The

valve pockets may be cast integral with either wall, but are preferably so attached to the inner, wall in .order to avoid leakage of the cooling medium `into lthe combustion` chamber. The annular openings surroundthe scope 'of the claims may occurto persons i Y skilled in the art.

It is claimed and desired to secure by v Letters Patent: v

1. In an engine cylinder, inner and outer walls cooperating to form an lintervening space, a valve pocket spanning said space,

said pocket being rigidly attached to one of said Walls and being free from direct connection `with the other, and means rigidlyrcon-L nect'ing medial-portions of said walls-and" formed to permit free relative longitudinalA expansion of the end portions thereof.

2. In anlengine cylinder, inner and outer annular walls cooperating to form. an intervening space surroundingsaid inner fwall, a plurality of valveV pockets spanning said space adjacent to the ends of said walls,

said pockets being rigidly attached'to said inner wall and being free from direct connection with said outer wall,` andmeansrigidly connecting medial .portions of said.`

walls and formed to permit free relative longitudinal expansion of the wall ends adjacent to said pockets.

3. In an engine cylinder, inner and outer walls cooperating to form an intervening space, a valve pocket spanning said space, said pocket being east integral with one of said walls and being free from direct cast connection with the other wall, and a member' cast integral with and connecting said walls remote from said pocket, said member being formed to permit iree relative longitudinal expansion ot said walls adjacent to said pocket.

t In an engine cylinder, inner and outer annular walls cooperating to form an intervening space surrounding said inner wall, a valve pocket spanning said space adjacent to the ends of said walls, said pockets being cast integral with said inner wall and being free from direct cast connection with said outer wall, and a member direct connecting and cast integral with said walls between said pockets, said member being formed to permit free relative longitudinal expansion of said walls adjacent to said pockets.

In an engine cylinder, inner and outer walls cooperating to form an annular intervening space surrounding said inner wall, valve pockets spanning said space ad- `acent to the ends of said walls said pockets eing cast integral with one of said walls and being free from direct cast connection with the other, a rib extending longitudinally of the axis of said cylinder and direct connecting said walls between said pockets` and a member direct connecting said walls adjacent to each of said pockets.

6. In an engine cylinder, inner and outer walls cooperating to form an annular intervening space surrounding said inner wall, valve pockets spanning said space adjacent to the ends of said walls, said pockets being cast integral with said inner wall and being free from direct cast connection with said outer wall, ribs extending longitudinally of said cylinder and connecting said walls between said pockets, and members connecting said walls on opposite sides of said ribs` said members being detlectable in a direction longitudinally of said cylinder.

7. In an engine cylinder, inner and outer walls cooperating to form an annular' intervening space surrounding said inner wall, valve pockets spanning said space on opposite sides of the cylinder axis and adjacent to the ends of said walls, each of said pock-y ets being east integral with said inner wall and being spaced from said outer wall, a plurality of ribs extending longitudinally of said cylinder and connecting said walls between said pockets, and a plurality of members direct connecting said walls on opposite sides of said ribs, said ribs being deilectable about the axis of said cylinder and said members being detlectable longitudinally of said axis.

S. In an engine cylinder, an inner wall having valve pockets castv integral therewith and extending outwardly therefrom, an onter wall surrounding said inner wall and having openings therein spaced from the outer ends ol said valve pockets, and ribs directly connecting said walls and maintaining a spaced relation therebetween independently of' said valve pockets, said ribs being formed to permit tree relative longitudinal expansion of said walls adjacent to said pockets.

9. In an engine cylinder, an inner annular wall having a plurality of valve pockets cast integral therewith and extending outwardly therefrom, an outer wall surrounding said inner wall to form an intervening space and having openings spaced from the outer extremities of said pockets, a plurality of ribs cast integral with said walls between said pockets, and a plurality of spacing members connecting said walls adjacent to said pockets, said members being laterally deilectable longitudinally of the cylinder axis to permit relative longitudinal expansion of said walls adjacent to said pockets.

l0. In an engine cylinder, an inner annular wall having a plurality of valve pockets cast integral therewith and extending outwardly therefrom, an outer wall surrounding said inner wall to form an intervening space and having openings spaced Yfrom the outer` extremities of said pockets, a plurality of ribs cast integral with said walls between said pockets, and a plurality of spacing members connecting said walls adjacent to said pockets, said ribs being deflectable about the axis of said cylinder and said members being deflectable longitudinally of said axis.

1l. In an engine cylinder, inner and outer walls cooperating to form an annular intervening space, a plurality o'l ribs cast integral with the medial portion of both of said walls and extending longitudinally of the cylinder, and a plurality of 'adially disposed mem bers connecting said walls at the ends of said ribs.

12. In an engine cylinder, an inner wall` an outer wall surrounding said inner wall and spaced therefrom to form an annular intervening open ended space, and a plu rality of ribs cast integral with both of said walls and disposed within said space, said ribs being located remote from the ends of said walls to permit relative longitudinal expansion of said walls at said ends 13. In an engine cylinder, an annular inner wall, an outer wall surrounding and cooperating with said inner wall to form an annular space, a rib direct connecting the medial portions of said walls and extending longitudinally of the cylinder, and a radial member direct connecting said Walls at an end thereof. c

14. In an engine cylinder, an inner annular Wall, an outer annular Wall surrounding 5 `said inner Wall and spaced therefrom to form an annular intervening space, said Walls being free from direct connection adjacent to their ends, and a plurality of spacing mem.-

bers rigidly connecting medial portions of 10 said Walls Within said space, said members being formed to permit free relative l0ngia tudinal expansion of said Walls adjacent to said ends. v Y

` l5. In an engine cylinder, an inner Wall,

an outer wall surrounding said inner Wall and' spaced therefrom t0 form an annular intervening space, said Walls being free from direct connection adjacent to their ends, and a plurality of radially disposed spacing members cast integra-l with both of said Walls intermediate said ends, said spacing members being laterally defleetable longitudinally of the cylinder axis to permit relative longitudinal'expansion of said Walls at said ends. f

In testimonfg whereof, the signature of the inventor is a Xed hereto.

CARL G. SPRADO. 

